diff --git a/flake8_stripe/flake8_stripe.py b/flake8_stripe/flake8_stripe.py
index 62352de80..f394632be 100644
--- a/flake8_stripe/flake8_stripe.py
+++ b/flake8_stripe/flake8_stripe.py
@@ -126,13 +126,15 @@ def __init__(self, tree: ast.AST, filename: str):
         self.filename = filename
 
     def run(self) -> Iterator[Tuple[int, int, str, type]]:
-        if not self.filename.split('/')[-1].startswith("_"):
+        if not self.filename.split("/")[-1].startswith("_"):
             backcompat = False
             for node in ast.walk(self.tree):
                 # check node is a constant string that contains package is deprecated
-                if (isinstance(node, ast.Constant)
+                if (
+                    isinstance(node, ast.Constant)
                     and isinstance(node.value, str)
-                    and "is deprecated" in node.value):
+                    and "is deprecated" in node.value
+                ):
                     backcompat = True
 
             if not backcompat: